[LLVMdev] Register Coalescer does not preserve TargetFlag

Jakob Stoklund Olesen stoklund at 2pi.dk
Mon Aug 6 10:51:07 PDT 2012


On Aug 6, 2012, at 10:45 AM, Vincent Lejeune <vljn at ovi.com> wrote:

> Is it possible to "customise" INSERT_SUBREG and COPY instructions to add them an immediate operands ?
> I know that COPY is lowered using copyPhysReg() function in MachineTargetInstrInfo, but I'm not sure there is something equivalent for INSERT_SUBREG.

No, these instructions must be pure register copies. They can't have additional target-specific semantics.

You would need to insert target-specific NEG and ABS instructions instead.

/jakob




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